Efficacy of Tolvaptan on Fluid Management After Cardiovascular Surgery Using Cardiopulmonary Bypass

To investigate the efficacy of the selective vasopressin V₂-receptor antagonist tolvaptan in postoperative fluid management after cardiovascular surgery using cardiopulmonary bypass.

A retrospective cohort study.

A tertiary care center.

The study comprised 99 patients undergoing cardiovascular surgery using cardiopulmonary bypass.

Oral tolvaptan was administered after surgery.

Fifty-one patients treated with tolvaptan were compared with 48 patients treated with intravenous diuretics. Urine volume, the time interval until the patients' body weight returned to the preoperative value, and the length of oxygen dependency after extubation were assessed as surrogate markers for resolution of fluid overload. Urine output on postoperative days 1 and 2 was significantly higher in the tolvaptan-treated patients (29.2 v 20.1 mL/kg/day, p = 0.001; 43.0 v 27.4 mL/kg/day, p<0.001, respectively). Postoperative body weight returned to baseline in 49 tolvaptan-treated patients compared with 33 patients treated with intravenous diuretics (96.1% v 68.8%, p<0.001). Among those with successful body weight reduction, the time interval was shorter in the tolvaptan-treated patients (5 v 7 days, p = 0.006). The length of oxygen dependency after extubation also was shorter in the tolvaptan-treated patients (2 v 3 days, p = 0.006). The urine osmolarity reduction rate before and 4 hours after the first dose of tolvaptan emerged as a significant predictor of its efficacy with a cutoff point of 33.7%, sensitivity of 0.73, and specificity of 0.67 (p = 0.030).

Tolvaptan facilitated early improvement of postoperative fluid overload after cardiovascular surgery.